JPH0813487B2 - Mold thickness adjusting device for injection molding machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a mold thickness adjusting device used in an injection molding machine for injection-molding various resin products into a mold under pressure.

(Prior Art) Needless to say, an injection molding machine for injecting molten raw materials of various synthetic resin materials into a mold to obtain various products having a required shape and structure is widely known. There are both shape and horizontal models. In a vertical injection molding machine, the molding die is divided into a vertical movable mold and a movable mold, and in a horizontal injection molding machine, the molding mold is divided into a horizontal movable mold and a horizontal movable mold. The basic structure is common to both models, and the outline is shown in Fig. 1. Although the figure is an embodiment of the present invention,
Explaining the basic structure excluding the part related to the present invention, the frame 1 in the injection molding machine includes a bed (fixed plate) 2 and a top platen 3 fixed to the floor, both 2, 3
It is composed of a plurality of (for example, four) tie rods 4 which are connected at equal positions, and a fixed mold 5 serving as a lower mold is placed on the bed 2 so as to be replaceable and removable, because it is a vertical type in the illustrated example. On the other hand, a slide (movable plate) 6 is vertically mounted over the tie rod 4, and the slide 6 is a piston rod of a mold opening / closing cylinder 7 installed on the bed 2 side.
A movable die 8 which is held by 7a and serves as an upper die on this slide 6.
Is detachably attached, so that the movable die 8 faces the fixed die 5 through the die opening / closing cylinder 7 and can be lifted and lowered along the tie rods 4, and although not shown in the drawings. An injection device for molten resin material is connected to one of the molds. In this example, a plurality of mold clamping cylinders 9 are installed on the slide 6 in a tie rod-inserting manner so that both molds 5 and 8 can be clamped. The half nut plate 10 is mounted on the tie rod 4 so that it can be moved up and down, and the half nut 11, which is one member that surrounds the tie rod 4 and constitutes the mold thickness adjusting device, is mounted on the plate 10 together with the cover 12. Is installed. Now excluding the function of the mold thickness adjuster,
As for the main function of the injection molding machine, as is apparent from the figure, the movable mold 8 is closed to the fixed mold 5 via the opening / closing cylinder 7, and both molds are clamped by the mold clamping cylinder 9. By injecting under pressure into the mold, various products can be obtained according to the mold surface.When exchanging both molds 5 and 8 according to the product target, the mold Depending on the size, thickness, and thickness, the operation of initially positioning the movable die 8 as the upper die is essential. For this reason, a mold thickness adjusting device is used in this type of injection molding machine, and the prior art of the device will be explained with reference to FIGS. 1 and 2. That is, on the outer peripheral surface of the tie rod 4 at a predetermined position, there is formed a positioning screw portion 13 in which saw-toothed screw teeth 13a are arranged in a line in a circumferential shape over an appropriate length. 4 has a half nut plate 10 which is loosely fitted so as to be able to move up and down, and has screw teeth 11a having the same shape as the screw teeth 13a arranged in a central hole, and a half nut 11 which is divided into two parts from the center is provided with a tie rod 4 It is mounted via a cover 12 so as to be able to advance and retreat in a direction orthogonal to and can be moved up and down along with the half nut plate 10, and at the outer circumference of each half of the half nut 11, a positioning screw portion of the half nut 11 is provided. A piston rod 14a of a drive cylinder 14 such as a hydraulic cylinder as an engaging / disengaging drive member for the cylinder 13 is connected to the cylinder 1
4 is installed on the half nut plate 10,
As a result, each half of the half nut 11 advances and retreats, so that the positioning screw portion 13 and the positioning half nut 11 are engaged and disengaged. Further, in order to move the half nut plate 10 up and down, a screw type jack 15 which is moved up and down by rotation as an elevating member is installed on the slide 6 located below the plate 12 via the mold clamping cylinder 9. In addition, a gear motor 16 with a brake as a driving member for rotating the jack 15 up and down is also installed on the slide 6, and the motor 16 and the jack 15 are linked by a chain, a sprocket or the like.
By connecting with the jack 17, the jack 15 is rotated forward and backward to move the half nut plate 10 up and down. This mold thickness adjusting device functions as follows.

That is, bed (fixed plate) 2 and slide (movable plate) 6
When the fixed mold 5 and the movable mold 8 to be mounted on the slide are exchanged, it is necessary to position the movable mold 8 to be mounted on the slide (movable plate) 6 side first because of the thickness of the mold. The open / close cylinder 7 lowers the molds 5 and 8 into a closed state. In the half nut plate 10 that accompanies the die clamping cylinder 9, the half nut 11 is driven by the drive cylinder 14 so that its screw teeth
11a is a tooth 13a of the positioning screw portion 13 of the tie rod 4.
When the height end face of the screw tooth 11a is in abutment with the height end face of the screw tooth 13a as shown in FIG. 2, the screw portion 13 and the nut 11 are in a non-engaged state. However, the two do not engage as they are. Therefore, by raising the half nut plate 10 with the jack 15 provided on the slide 6 via the motor 16, the screw teeth of the nut 11 are
11a automatically engages the screw teeth 13a, and the jack 13
By stopping the, the positioning set (mold thickness adjustment) of the movable die 8 can be obtained. The one illustrated in FIGS. 1 and 2 is an example of a vertical injection molding machine, which includes a positioning screw portion 13 formed at a predetermined position of a tie rod 4, and a threaded portion surrounded by the moving cylinder 14 by a moving cylinder 14.
The mold thickness adjusting device, which has a half nut 11 that is disengageably arranged with 13 as a main component, is common in this type of injection molding machine regardless of whether it is vertical or horizontal, and the half nut 11 is attached to the tie rod 4. Although not shown in the drawing, the contents of the drive mechanism that moves the screw teeth 11a along with the screw teeth 13a of the positioning screw portion 13 on the side of the tie rod 4 in the fixed position or the installation position thereof are not shown. Is also known to exist. For example, in a vertical type, a drive mechanism (motor 16, interlocking mechanism 17, etc.) is installed on the top platen 3, and a screw shaft that can be rotated forward and backward is penetrated through the half nut plate 10 by the drive mechanism. Adjustable nuts or stoppers that can be raised and lowered through forward and reverse rotations on the screw shaft, and the half nut plate 10 is moved by the nuts or stoppers so that the half nuts 11 are tuned and meshed, or horizontal type In this case, the bed (fixed plate) 2 and the slide (movable plate) 6 are placed side by side, but a half nut 11 is installed on the slide (movable plate) 6 and is parallel to the tie rod 4. A half-clamping cylinder 9 is provided to move and synchronize the half nut 11 along the tie rod 4, or the half nut 11 is provided on the bed (fixed plate) 2 side. A half nut plate 10 that can be driven is provided so that it can be driven, and a plurality of locking portions are provided in a row on a tuning bar that is provided in parallel with the tie rod 4 on the side of the slide (movable plate) 6, and the locking collar can be replaced with this. It is also known that there are those that regulate the movement amount of the half nut plate 10.

(Problems to be Solved by the Invention) The above-described conventional mold thickness adjusting device in an injection molding machine has the following problems. That is, in the prior art,
For the positioning lock, which is the main operation of the mold thickness adjusting device, the half nut 10 and the tie rod 4 positioning screw part
In determining the meshing position with 13, the preliminary half nut 10 is pressed against the tie rod 4 side under low pressure, and the half nut plate 10 is moved by a jack or other moving member to be meshed. In the above, an unreasonable external force acts on both the screw teeth 13a of the positioning screw portion 13 and the screw teeth 11a of the nut 10, and the two teeth may be damaged by being brought into contact with each other by twisting and moving. Furthermore, in the meshing by sliding movement of both teeth, reliability is lacking in properly and accurately determining the meshing position, and further, the moving member such as the jack 15 for moving has the half nut plate 10, In addition to the total weight of the half nut 11, frictional force on the screw teeth 11a and 13a is also applied, and a large driving power is required, which is disadvantageous.

Further, in the case of restricting the movement amount of the half nut plate 10 by locking the locking collar to the locking portion of the tuning bar, the work of attaching the collar to the locking portion is done by the operator's hand. It is dangerous because it is carried out. In addition, stepwise adjustment cannot be performed with the engagement portion and the collar, and the die thickness cannot be adjusted corresponding to a die having an arbitrary die thickness. Further, there is a problem in that the weight of the device is increased by the amount of the tuning bar and the device is increased in size.

(Means for Solving Problems) In order to solve the above problems, the present invention applies a load only to the screw teeth of the tie rod and the half nut described above only in a completely meshed state, and It enables good positioning, and enables compactification of the overall driving members such as jacks. Specifically, it is a fixed type fixed on the frame side of the injection molding machine and And a movable die which can be opened and closed by being held along the tie rod belonging to the frame, and can be moved in the same direction as the movable die and along the tie rod to the positioning screw portion formed on the tie rod. In which the positioning half-nut arranged in the above-mentioned manner is reciprocally engaged with the tie rod by advancing and retreating in a direction orthogonal to the tie rod. A detection member for detecting an appropriate meshing position of both screw teeth in the half nut screw portion is provided between both screw portions.

(Operation) According to the above-mentioned technical means of the present invention, as shown in FIGS. 1 and 2, in the example shown in FIG. 1, a vertical injection molding machine is used. ) The stationary die 5 is fixed on the tie rod 2, the movable die 8 is attached to the slide (movable plate) 6 slidably held over the tie rod 4, and the tie rod 4 is surrounded on the slide (movable plate) 6. A mold clamping cylinder 9 is provided, and a half nut plate 10 mounted slidably over the tie rod 4 above the cylinder 9 encloses a positioning screw portion 13 formed at a predetermined position of the tie rod 4 to surround the half nut plate 10. Nut 11,
The moving member of the half nut plate 10 is provided on the slide (moving plate) 6 so as to be engaged with and disengageable from the positioning screw portion 13 by advancing and retracting in the direction orthogonal to the tie rod 4 via the drive cylinder 14. As jack 15
In the example shown in the figure, the half nut plate 10 is fixedly arranged and the half nut 11
In the cover 12 that encloses the, the detection member 18 for detecting that the screw teeth 13a of the positioning screw portion 13 of the tie rod 4 and the screw teeth 11a of the half nut 11 are in the proper meshing position (Fig. Then, by installing a magnetic sensor that directly detects the tooth height of the screw teeth 13a of the positioning screw 13 of the tie rod 14, the positioning of the half nut 11 for positioning the movable die 8 is performed as follows. It is possible to perform a tuning engagement operation with respect to the screw portion 13. That is, in the same manner as in the case of the prior art, the half nut plate 10 is moved together with the jack nut 15 to move the screw teeth 11a of the half nut 11 and the screw teeth 13a of the positioning screw portion 13 into mesh with each other. It is placed in the open position through the pre-driving cylinder 14, and the jack 15 is raised to move the half nut plate 10, and accordingly the half nut 11 and the cover 12 on the plate together, and the detection member 18 causes the screw teeth to move. At the time when it is detected that both 13a and the screw teeth 11a have reached the proper meshing position, the jack 15 is immediately stopped by the detection member 18 via a detection signal, and then the driving cylinder 14 is driven to half-drive. By moving the nut 11 forward to the closed position, a smooth and resistanceless meshing operation of the screw teeth 13a, 11a can be obtained, and the half nut 11 can be moved by the pre-driving cylinder 14 as in the conventional case. Although the Iroddo 4 side is low placed by pressure contact under pressure, the movement of the half nut plate 10 by the jack 15, both teeth under pressure 11
a, 13a do not move and mesh with each other in a prying manner to prevent damage to both screw teeth 11a, 13a, and reduce the load on the jack 15 and the drive cylinder 14 to reduce the load on the device. The compactness can be obtained.

(Example) An appropriate example of the mold thickness adjusting apparatus according to the present invention will be described with reference to FIGS. 1 to 3. An example of a vertical injection molding machine is shown in the embodiment. However, as is clear from the description of the prior art described above, the vertical injection molding machine has a positioning screw portion 13 formed on the tie rod 4 regardless of whether it is vertical or horizontal. Needless to say, all types can be applied to a type in which positioning is performed by using the half nut 11 that surrounds this and is openably and closably arranged on the half nut plate 10.

As is known from the vertical injection molding machine shown in FIG. 1, the molding machine frame 11 includes a bed (fixing plate) 2 fixed to the floor and a top platen arranged in parallel with the bed (fixing plate) 2. 3, a tie rod 4 for connecting the two equally divided positions of the two and 3, for example, a fixed die by a mold is detachably mounted on the bed 2 and slides over the entire tie rod 4. A movable die 8 made of a metal mold is detachably attached to a slide (movable plate) 6 which is mounted as possible, and a piston of a die opening / closing cylinder 7 installed on the bed 2 side is attached to the slide (movable plate) 6. By connecting the rod 7a, opening and closing of both types 5 and 8 are performed. On the upper surface of the slide (movable plate) 6, for example, in two tie rods 4, 4 at symmetrical positions, mold clamping cylinders 9 are respectively arranged so as to surround the tie rods 4 in a tie rod penetrating manner. Fixed to the slide (movable plate) 6 side, the piston rod or ram is the half nut plate 10
I will head to the side. Half nut plate 10 over all tie rods 4 above the same-shaped clamping cylinder 9.
Is slidably mounted.

On the outer peripheral surface of the two tie rods 4 in the same symmetrical position of the plate 10, as shown in FIG. 2, positioning screw parts 13 in which serrated screw teeth 13a are arranged in a row over an appropriate length are formed. A known half nut 11, which is split in half and surrounds the positioning screw portion 13, is openable and closable, and is located inside a cover 12 that is fixed to the plate 10 by enclosing the nut 11 and fixedly mounted on the plate 10. Mounted on 10. The inner peripheral surface of the center hole of the nut 11 is provided with saw tooth-shaped screw teeth 11a corresponding to the screw teeth 13a in a row, and at the upper surface fixed position of the cover 12, the positioning screw portion 13 side in the embodiment. A detection member 18 by a magnetic sensor for directly detecting the tooth height position of the screw tooth 13a is fixed. A piston rod 14a of a drive cylinder 14 for opening and closing, which is installed on the half nut plate 10, is connected to the outer peripheral surface of each of the two half nut pieces of the half nut 11. On the board 6, two screw type jacks 15 are installed at symmetrical positions as driving members for vertically moving the half nut plate 10. In the embodiment, as a common drive source for the jacks 15 and 15, one motor 16 with a brake is installed on one side of the slide (movable plate) 6, and the motor 16 and the two jacks 15 and 15 are different from each other. For example, a plurality of endless chains, a plurality of sprockets for connecting and rotating the chains, and the like are connected by a transmission mechanism 17, and the jacks 15 and 15 can be synchronously driven to move up and down.

In FIG. 1, 19 is a limit switch for confirming the descending (retracting) limit of the slide (movable plate) 6 disposed on the slide (movable plate) 6 side (for confirming the descending limit of the jack 15), 20
Corresponding to this, for confirmation of close contact placed on the side of jack 15 (for confirmation of close contact between jack 15 and half nut plate 10)
The proximity switch is shown. In the vertical injection molding machine, in addition to this embodiment, a moving mechanism for the half nut 11 is installed on the top platen 3 and a stopper or nut capable of moving up and down is operated on the half nut plate 10 side. In some cases, the half nut plate 10 having the half nut 11 and the positioning screw portion 13 are provided on the lower side of the slide (movable plate) 6 instead of the upper side, but the present invention is naturally applied to these. In addition, in a horizontal injection molding machine, basically, the illustrated one is turned over 90 degrees to horizontally face the bed (fixed plate) 2 and the slide (movable plate) 6. In this type, the tie rod 4 is inserted through the bed (fixing plate) 2 and is also used as the ram or piston rod of the mold clamping cylinder, or one end of the tie rod 4 is There is a type in which the pad (fixed plate) 2 is inserted, and the half nut 11 is provided on the same side of the bed (fixed plate) 2 so as to surround the insertion end. It is possible to apply the mold thickness adjusting device in.

In the embodiment, a direct detection type magnetic sensor is used as the detection member 18, but it is also effective to use a high precision displacement meter instead of the magnetic sensor, and as shown in FIG. As a known means, the meshing position detecting dummy plate 22 in which the light transmitting holes 21 are arranged in line under the correct meshing pitch interval L between the screw teeth 13a of the positioning screw portion 13 and the screw teeth 11a of the half nut 11 is provided. It is also possible to use a photoelectric sensor 23 or a magnetic sensor, which is arranged between the light emitting portion 23a and the light receiving portion 23b, the detection member 18 can be freely selected, and for moving the half nut plate 10. As the driving member, in addition to the screw type jack, an electric jack or a fluid pressure cylinder having a forward / backward position securing means (lock means) for the ram or piston rod can be used.

(Effects of the Invention) According to the present invention, there is a problem in the prior art in this type of injection molding machine, that is, unreasonable prying contact and moving friction of both screw teeth 13a, 11a in the positioning screw portion 13 and the half nut 11. It is extremely effective in solving the problems of damage due to damage, lack of reliability for proper meshing of both teeth, and excessive load capacity of the jack 16 and the drive cylinder 14. That is, since it is not necessary to press the half nut 11 against the tie rod 4 side under pressure, the load is applied only when the screw teeth 13a, 11a reach the complete meshing position. The drive load of 15 and the drive load of the drive cylinder 14 are both smaller than in the conventional case, the load of only the weight of the half nut 11 and the plate 10 is applied to the jack 15, and the drive cylinder 14 is constant when the nut 11 is closed. Since only the pressure required for opening and closing is sufficient, it is sufficient for both equipment structures to have a small capacity, and the cylinder 14 has a small capacity, a compact size, and a jack.
15 and the driving motor 16 can be easily made small in output and compact, and the screw teeth 13a can be accurately and smoothly smoothed.
The meshing of 11a is obtained, which contributes to the improvement of the durability and reliability of the entire mold thickness adjusting device.

[Brief description of drawings]

FIG. 1 is a front view of an example of a vertical injection molding machine using an embodiment of the device of the present invention, FIG. 2 is a side sectional view of the main part of the device, and FIG. 3 is a front and side view of the embodiment of the detection member. is there. 1 ... Molding machine frame, 2 ... Bed (fixed plate), 3 ...
… Top platen, 4 …… tie rod, 5 …… fixed type,
6 ... Slide (rotating plate), 7 ... Cylinder for mold opening and closing,
8 ... Movable type, 9 ... Mold clamping cylinder, 10 ... Half nut plate, 11 ... Half nut, 12 ... Cover, 11
a, 13a …… Screw teeth, 14 …… Drive cylinder, 15 …… Jack, 18 …… Detecting member.

Front page continuation (72) Inventor Masanobu Masanobu 2-3-3 Konan-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture 10-508 (72) Inventor Susumu Nakamitsu 3-11-8, Sumiyoshihoncho, Higashinada-ku, Kobe-shi, Hyogo Prefecture No. 405 (72) Inventor Takeshi Sano 8-5404 Tsuchiyama-cho, Nada-ku, Kobe-shi, Hyogo

Claims (1)

[Claims] 1. A tie rod, which comprises a fixed die fixedly placed on the frame side of an injection molding machine and a movable die which can be opened and closed toward the fixed die and is held along a tie rod belonging to the frame. A positioning half nut, which is movably arranged in the same direction as the movable die and along the same tie rod, is provided on the positioning screw portion formed in
In a structure for advancing and retreating in a direction orthogonal to a tie rod and engagingly and disengageably engaging, a detection member for detecting a proper meshing position of both screw teeth in the positioning screw portion and the half nut screw portion is provided between both screw portions. Mold thickness adjusting device for injection molding machine.